tests: Add test for updating from oci remote (currently broken)
tests: Add test for updating from oci remote (currently broken)

This is currently failing with:
  Can't pull from untrusted non-gpg verified remote

Closes: #2891
Approved by: alexlarsson

matthiasclasen/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak